"As the matter is now before the Court of Appeal, no further comment is appropriate," he added.
Professor Maan Alkaisi, whose wife Maysoon Abbas died in the collapse, gave a press conference this afternoon on behalf of the CTV Families Group, reacting to the appeal news. Alkaisi is still battling for "justice and accountability" seven years after the tragedy.
The CTV Families Group was "clearly disappointed" by the appeal and its inevitable delays, Alkaisi said.
He said they had fully endorsed the High Court decision and hoped that the Court of Appeal would also find that Engineering New Zealand could reopen its investigation into a complaint against Reay.
"This is about ethical, professional and legal obligations expected from a practicing engineer," Alkaisi said in a press conference at the former CTV site, which is now a memorial garden space.
"After almost eight years since the CTV collapse, we know all the details of the defective design, how and why the building collapsed and who is responsible for that.
"Yet, to date, no one was held to account and there has been no closure for the families who lost loved ones, no accountability, and no justice. The Engineering NZ investigation provides an opportunity for this."
He added: "We will not be silenced to ask for the truth, to ask for accountability, and to ask for justice. Never underestimate the strength and determination of people asking for justice. The story of the CTV Building collapse will only end when justice is done."
Former Building Minister, engineering fellow, and Nelson MP Dr Nick Smith slammed the appeal.
"It is disgraceful that eight years after the CTV building collapsed, killing 115 people, the Institute for Professional Engineers has not been able to conclude its investigation," he said.
"These ongoing legal shenanigans are unfair on the families of the CTV Building victims and is undermining New Zealand's confidence in our systems for holding professionals accountable. This case is turning into one of justice delayed, resulting in justice denied."
Smith said it was "unacceptable" that a professional - be they an engineer, doctor, lawyer or any other - can "avoid accountability by resigning from the professional body, particularly in a case as serious as this where 115 people died".
"I am appalled as a Fellow of the Institute of Professional Engineers and as a Member of Parliament at the way the disciplinary system has been gamed for years to avoid professional accountability," Smith said.
"Dr Reay has dumped on his junior engineer, contested the Royal Commission's technical conclusions, challenged the composition of the Institute's Investigating Committee, questioning the Attorney-General's standing in bringing the judicial review proceedings and is now appealing the decision of the High Court.
"These years of delays means we need the appeal to be resolved urgently. The appeal only enables the Institute to consider the investigation and decide whether to initiate the Disciplinary Committee process that will still take significant time.
"This investigation and disciplinary process is not just important for justice for the CTV families. The engineering profession needs to ensure every possible lesson is learnt from this tragedy. A particularly important area from this case is clarifying the professional responsibilities and accountability of senior engineers and those working under them to guide and improve future practise."
Smith has today written to Attorney-General David Parker, "with the full support of the CTV families", encouraging the Government to seek urgency on the appeal.
"We owe it to the CTV building victims' families and the wider New Zealand public to get these issues resolved," he added.
A Royal Commission of Inquiry into the Canterbury earthquakes criticised Reay for giving his inexperienced structural engineer David Harding "sole responsibility" for the building's mid-1980s design.
The six-storey Christchurch office block pancaked in the February 22, 2011, earthquake, killing 115 people.
The chief engineer for Ministry of Business, Innovation and Employment (MBIE) made a complaint to Ipenz about Reay's involvement in the CTV Building in 2012.
But Reay resigned his voluntary membership of the institute in February 2014 while the professional body was investigating the complaint and later decided not to pursue any disciplinary action against him. Ipenz concluded it no longer had jurisdiction to deal with a former member.
A September 2014 decision by the High Court relating to Harding ruled that an investigation and disciplinary hearing could continue even when a member resigned.
In 2017, a long-awaited police probe concluded no criminal charges would be laid despite "significant" design deficiencies.
The Attorney-General filed for a judicial review of the Ipenz decision in 2015.
"It is important that we clarify the law as to whether a professional can avoid disciplinary proceedings by simply resigning," then Building and Housing Minister Dr Nick Smith said in March 2015.
"Completing the Ipenz investigation will also be important in clarifying the professional standards expected of a senior engineer supervising the work of a more junior engineer."